Best Tire Choice for AP1 running OEM 17s in New England weather?

Reply Subscribe

Thread Tools

05-18-2017, 03:45 PM

#11

Bama Dave

Community Organizer

Join Date: Nov 2010

Location: Somewhere in the Sun Belt

Posts: 4,054

Likes: 100

Received 204 Likes on 162 Posts

Quote:

Originally Posted by Chuck S

Just curious: Are 17x9 wheels gonna fit all around? OEMs are 7" and 8.5" (F/R)? 215mm tire on a 9" rim?

Beware of TW ratings, they're manipulated by tire manufacturers to fit the (mis)conception that the lower the number the better the grip. Just slap a low number on a mediocre tire and ***Poof*** it's a performance tire!

Test results will tell more. Really sticky tires will have lower TWs but the reverse ain't always true.

-- Chuck

I'm running them on both cars at stock ride height with no problems. The 245 or 255 on the 9" wheels, the inside of the rim will rub on the front lower control arm at full left turn lock. You are correct Chuck with the tread wear ratings. Each manufacturer has their own specs. Later BD

Last edited by Bama Dave; 05-18-2017 at 03:51 PM.

Reply Like

05-18-2017, 04:32 PM

#12

plato

Registered User

Thread Starter

Join Date: May 2016

Posts: 27

Likes: 0

Received 0 Likes on 0 Posts

After reading the stickies, the thing is that both the AP1 with OEM 16s and AP2 with OEM 17s on OEM tires had a much higher ratio rear to front tire tread contact widths. But those tires are not available any more. Looking at the following ratios (front vs rear tires and vice versa), it seems that the 215/255 Conti gives you the highest rubber ratio at the back, though there's a 0.4 inch difference in height which might be visible. The math says the square setup will increase oversteer (too much traction on the front) and reduce steering feel, not looking to do that.

Right now, I'm running Continental DSWs on 16s 205/225 with a tread of 6.7" / 7.4" (r/f=1.104 or f/r=0.905), which is not right. The original AP1 tires were 6.9"/8.4" (r/f= 1.217 or f/r=0.821). The AP2s OEM tires had 6.7"/9.0" tread width which results in r/f= 1.343 or f/r=0.744.

Continental vs Bridgestone S-O4s Tread Widths

215/245 Bridgestone S-04: 7.7" f / 9" r tread width = 1.168 r/f (or 0.855 f/r) DIAMETER 24.7" both
215/245 Continental Extremecontact Sport: 7.3" f / 8.6" r tread width = 1.178 r/f (or 0.848 f/r) DIAMETER 24.6 " f / 24.7" r

215/255 Bridgestone S-04: 7.7" f / 9.2" r tread width = 1.194 r/f (or 0.837 f/r) DIAMETER 24.7" f / 25" r
215/255 Continental Extremecontact Sport: 7.3" f / 8.8" r tread width = 1.205 r/f (or 0.829 fr) DIAMETER 24.6" f / 25.0" r

225/255 Bridgestone S-04: 8.1" f / 9.2" r tread width = 1.130 r/f (or 0.880 f/r) DIAMETER 25" both
225/255 Continental Extremecontact Sport: 7.6" f /8.8" r tread width = 1.157 ( or 0.863 f/r) DIAMETER 25" both

Last edited by plato; 05-19-2017 at 08:26 AM.

Reply Like

05-18-2017, 08:04 PM

#13

Car Analogy

Join Date: Aug 2012

Posts: 7,851

Likes: 0

Received 1,315 Likes on 993 Posts

Quote:

Originally Posted by EELPIE

I went with the 215/255 combo because I am running the CR shocks and springs and a AP2 rear sway bar. So I wanted to match CR sizes if not compounds.

I'm glad you like your setup. That is what really matters. FYI though, its a misconception that matching the CR stock sizes should choose 215/255. Yes, that is the sizes used with the oem RE070. But the specs for physical dimensions of those tires more closely match ap2 215/245 for most other tires.